| → not furnished with membrane, of the 1866 1869 |
| of 1859 1860 1861 |
| not furnished with membrane of the 1872 |
|
| → —the water-hen and landrail are members of this order, yet the first 1866 1869 |
| yet the water-hen 1859 1860 |
| — yet the water-hen 1861 |
| — the water-hen 1872 |
|
| → is 1859 1860 1861 1866 1869 |
| and landrail are members of this order, yet the first is 1872 |
|
|
we now see it, must occasionally have felt surprise when he has met with an animal having habits and structure not
in agreement. What can be plainer than that the webbed feet of ducks and geese are formed for swimming?
there are upland geese with webbed feet which rarely
go near the water; and no one except Audubon has seen the frigate-bird, which has all its four toes webbed, alight on the surface of the
On the other
grebes and coots are eminently aquatic, although their toes are only bordered by membrane. What seems plainer than that the long
→not furnished with membrane, of the
are formed for walking over swamps and floating
→—the water-hen and landrail are members of this order, yet the first
→is
nearly as aquatic as the
and the
nearly as terrestrial as the quail or partridge. In such cases, and many others could be given, habits have changed without a corresponding change of structure. The webbed feet of the upland goose may be said to have become
in function, though not in structure. In the frigate-bird, the
membrane between the toes shows that structure has begun to change. |
|
| He who believes in separate and innumerable acts of creation
say, that in these cases it has pleased the Creator to cause a being of one type to take the place of one
another type; but this seems to me only
the fact in dignified language. He who believes in the struggle for existence and in the principle of natural selection, will acknowledge that every organic being is constantly endeavouring to increase in numbers; and that if any one
ever so little, either in habits or structure, and thus
an advantage over some other inhabitant of the
it will seize on the place of that inhabitant, however different
|
